Join the conversation
Subcribe to comment rss feedMore on depth of field
Tim Parkin
Amateur Photographer who plays with big cameras and film when in between digital photographs.
Our last article on depth of field took an overview of all of the ‘techniques’. This article is the first one to look into depth of field in depth but don’t worry, we’ll also break out now and again to give you some simple ideas for use in the field.
The first thing to cover is “What is depth of field?”. A lot of people have the assumption that everything in the “depth of field” is sharp and everything outside it is blurry. Nothing could be further from the truth. In reality we only have less blurry and more blurry, only occasionally do we reach truly sharp. Depth of field is all about working out what ‘acceptably blurry’ is.
Circle of Confusion (or 'Amount of Blur')
To understand this we need to take a look at what blur is. If you look at the following diagram, which is based on taking a photograph of a star in the night sky, you can see that light rays converge on a point, either side of that point.